Which of the following code segments can be used to interchange the values of the variables num1 and num2?
A
num1 ⇔ num2
num2 ⇔ num1
B
temp ⇔ num1
num1 ⇔ temp
num2 ⇔ num1
C
temp ⇔ num1
num2 ⇔ num1
num1 ⇔ temp
D
temp ⇔ num1
num1 ⇔ num2
num2 ⇔ temp
The correct answer is D.
Explanation:
In option D, the steps performed are:
1. `temp ⇔ num1`: Store the value of `num1` in `temp`.
2. `num1 ⇔ num2`: Assign the value of `num2` to `num1`.
3. `num2 ⇔ temp`: Finally, assign the value stored in `temp` (original `num1`) to `num2`.
This effectively swaps the values of `num1` and `num2`. Other options do not correctly perform the swap without losing one of the values.